While most proposals for future space exploration involve trips to the Moon or Mars, we don't actually have to land anywhere to break new ground. This plan would establish an outpost further from Earth than any human has ever gone.
The idea, which NASA is currently trying to develop into a full-fledged plan, would involve setting up a "human-tended outpost" at one of the Lagrangian points. Also known as libration points, these are locations in the Earth-Moon system where the gravitational pull of the two bodies balance each other out, making it possible to "park" space stations there with relative ease.
There are five Lagrangian points. The first, or L1 is the most intuitive, located between Earth and the Moon. L4 and L5 roughly share the Moon's orbit but at each a distance of sixty degrees away. L3 is also more or less on the Moon's orbit, just 180 degrees away. Finally, there's L2, which is located on the far side of the Moon at a point where the combined gravitational effect of the Earth and Moon places any object there in an orbit whose period matches that of the Moon's, meaning they orbit the Earth in the same amount of time.
This particular plan calls for an outpost at L2, which is 37,000 miles beyond the Moon. This would easily beat the current record for the furthest any human has traveled from Earth, set by the Apollo 13 astronauts when they were forced to go around the Moon on a free return trajectory.
This outpost would serve as a potentially ideal jumping-off point for crewed missions to the Moon, asteroids, and Mars and its moons. It would also provide a much-needed test of the potential for long-term human survival outside the Van Allen radiation belts that protect Earth and those in low-Earth orbit. Finally, there are plenty of scientific experiments and observational work that can be done in the relative peace and quiet of L2 that could not easily be duplicated either on Earth or the Moon.
For some more technical details on this idea, check out Space.com.
Image via NASA.